Re: RFC: ldconfig speedup

[Jakub Jelinek <jakub at redhat dot com>]

On Tue, Jul 03, 2007 at 01:45:13PM -0700, Ulrich Drepper wrote:
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> Andreas Jaeger wrote:
> > What do you think now?
> 
> Lot's of formatting and little style/semantic problems all over the place.

...

I haven't seen any progress with this, so in order to speed up the process
I tried to address all issues Uli and Jim raised plus several minor or
less minor things.

Attached is a new patch, plus interdiff from the last patch Andreas posted.
I have briefly tested it, but nothing extensive.

The remaining issues I'd like to discuss before changing them are:

1) ldconfig uses the /var/cache/ldconfig/aux-cache cache only to speed up
   mapping of the cache_entry_id -> { flags, osversion, soname }
   so what's the point of aux_cache_file_entry containing value (aka path)
   or hwcap?
2) the aux_entries linked list will usually contain roughly 2000+ entries,
   isn't that above the count where using a simple hash table or rb tree
   (hsearch_r is probably a bad idea, as it needs strings as keys,
   but we could either implement our own trivial hash table
   (say hashing with nextprime (aux_cache->nlibs) hash table
   entries with chains), or could grab from libiberty Vlad's hashtab.c
   (that's probably overkill, we know how many entries we have, no need
   to ever resize it), or use tsearch).
3) couldn't the aux-cache entries also contain negative lookups?
   E.g. we have *.so linker scripts in the directories, that can be
   cached as cache_entry_id -> { -1, -1, 0 } or something similar
   to denote non-DSO.

	Jakub

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